Process for the manufacture of lustrous threads from crude viscose by means of warm mineral acids



arana" orrica.

EMILE BRQIINERT, OF NIEDERMO RSCHWI BIQER, IIIULHAUSEN, GERMANY,ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE CHEMICAL FOUNDATION, INC-,1;

a coaroaa'rron, or DELAWARE.

PROCESS FOR THE UFACTURE OF LUSTBOUS THREADS FROM. CRUDE VISC OSE BYMEANS OF WARM HCINERAL ACIDS.

No Drawing.

To all whom it may concern:

Be it known that I, EMILE BRONNERT, a sub ect of the Emperor of Germany,residing at'Niedermorschweiler, near Mulhausen,Al-

sace, Germany, have invented certain new and useful Improvements inProcesses for the Manufacture of Lustrous Threads from Crude Viscose byMeans of Warm Mineral Acids; and I do hereby declare the following to bea full, clear, and exact description of the invention.

This invention relates to processes for the manufacture of lustrousthreads (artificial silk), sheets, films, and the like from crudeviscose, by the use of warm mineral acids, and aims to provideimprovements in such processes, and in the articles produced thereby. vI

British Patent 17503/1902 recommends the use of a 10 per cent solutionof sulphuric acid for the spinning of crude viscose (Bohviscose),stating that the sulphur separating out on the decomposition of theviscose can be'subsequently again removed with sodium sulphide. Theprocess, however, found no application, since the de-sulphured threadswere brittle and had but little luster.

centigrade, as a precipitating bath. German.

Patent 187947/1905 had for the first time found another way in'which toemploy the sulphuric acid for the spinning of crude viscose. .This meansconsisted in adding a predetermined amount of the salt of the acid,

to thus remove the violence of the decomposition reaction and to allowthe threadto be produced under more favorable conditions.

Later it was found that glucose and other organic ,bodies actedsimilarly to salts upon Specification oi Letters Patent.

Patented isms-{1922.

Application filed January 8, 1914. Serial No. 811,060.

the acid and consequently upon the threads In a surprising mann it hanow been produced.

shown that the crude viscose can be also spun with a mineral acid, suchas sulphuric acid,

without any addition, if on the one hand concentration and temperatureof the acid are adapted to the age of the viscose to be emplo ed. A

11 general, the crude viscose be' SO much the older as the acid chosenis more concentrated and warmer. 1

The methods of determination of the nec essary condition of theviscosesolution in" each single case are unfortunately we unreliable to berecommended. If, however, the alkali cellulose has been left to itselfin the well-known manner first for two or three days at about 20 to 25C. and then the viscose solution made therefrom has been left for acertain number of days at a constant temperature of from 17 to 22centigfade, then the same. conditions can at any time be easily againproduced which are necessary for assuring a constantly equal product,and which have been recognized once for all as such by means of expertmethodical preliminary experiments.

Example l.-Crude viscdse which has stood about eight days or more at 15to 20 centlgrade and has been several times filtered is forced into warmsulphuric acid of a strength of 20 per cent at 40 0., wound .on

suitable bobbins, and then or afterwards washed with warm water and inwell known manner under tension" dried and de'sul plnu'ed.

Example I I Crude viscose which has stoodabout four days or longer at 15to 20 .C. after filtering is forced into lO-per cent acid at atemperature of 25 C. or warmer or of equivalent quantity of anothermineral acid ,while drawing the thread through it for a length, forexample,.of only three centimeters, and then, as in Example I, againwashed and dried and de-sulphured under tension. 3 p I claim as myinvention:

.1. Proces for the manufacture of lustrous threads from viscosecomprising directly transforming crude viscose into such threads byforcing it in the form of a cor- 1' ii respondingly shaped stream into athread thus formed ihread being capable (if being Wound uppn suit-ablebobbins.

2. A. process for the production of lus- ;.trous threads from viscosecom rising a1- lowirigficrude' viscose to stand a ut eight days or moreunder 15 te 20 degrees C. terns 'pemtilre, filtering, mid forcing itinto a misses warm befii of suiphuricacidflf about 20% concentrationanci about 420 degrees C; tem-- perature, winding upon suitable behbins,ashing with Warm Water in wel}. known manner, drying and desulphuring.

In witness whereef, I have hereunto signed my name in the presence (1fawe subscribing witnesses. i i v EMILE BRUNEI E1837;

\Vitnesses':

PHILIP-HOILAND, ARNOLD ZUBER,

